Turbomachine

ABSTRACT

A turbomachine has at least one novel integral runner assembly formed by a centripetal inducer portion and a centrifugal impeller portion, both of which include a plurality of circumferentially spaced vanes in the vicinity of each periphery. An intermediate shroud separates the vanes of each portion and, together with a forward and rearward shroud, establishes a space through which fluid flow in a generally oblique meridional flow pattern is conducted from the trailing edge of an centripetal inducer vane to the leading edge of a centrifugal impeller vane. The integral runner assembly is disposed within a housing including means to present a radial flow of fluid for entry into the centripetal inducer portion and additional means at the outlet of the integral runner assembly to remove all tangential vector components of flow in order to impart to the flow an axial direction.

United States te t 1191 111] 3,

Zerrer 5] Dec. 9, 1975 TURBOMACHINE 843,638 4/1939 France 415/143 7242,855 11/1925 United Kingdom 415/198 [76] Inventor Zerrer Box 25,1091907 United Kingdom 415/219 c Easton, 21601 1,279,260 11/1961 France415/198 [22] Filed: Sept. 27, 1973 [21] Appl. N0.: 401,403 PrimaryExaminer-Henry F. RaduaZO Attorney, Agent, or Firm-Pennie & Edmonds [52]US. Cl 415/143; 415/198; 415/219 C;

417/423 R [51] Int. Cl. F04D 17/02 7 TRQ [58] Field of Search 415/120,198, 219 C, 215, [5 ABS CT 415/143 A turbomachine has at least one novelintegral runner assembly formed by a centripetal inducer portion and[56] References Clted a centrifugal impeller portion both of whichinclude a UNITED STATES PATENTS plurality of circumferentially spacedvanes in the vi- 846,971 3/1907 Akimoff 415/120 cinity of eachperiphery. An intermediate shroud sepa- 854,012 5/1 0 Akit fi' 4 ratesthe vanes of each portion and, together with a gavldsonk i gfigz forwardand rearward shroud, establishes a space awacze l 1,363,315 mm M.417/422 ggg gg y 'gggg g1 3153 3 5535 gg lggg ggfg 2,265,806 12/1941Goldschmied 415/198 f P l d 1 g g 2,395,704 2/1946 Wislicenus 415/198 0P m ucer the ca mg edge Ofa 2,422,763 6/1947 Wislicenus... 260/268centrlfilgal Y f' {unner assem- 2,471,892 5/1949 Price 1 415/120 bly 1Sdlsposed Wlthm a houslng lncludmg means to 2,985,108 5/1961 s e; et a1,415/120 present a radial flow of fluid for entry into the centrip-3,069,071 12/1962 Carlson 415/1 16 etal inducer portion and additionalmeans at the outlet 3,1 8 9/ 3 Sto et 4l5/l20 of the integral runnerassembly to remove all tangen- 3,305,l65 2/ 1967 e y 415/211 tial vectorcomponents of flow in order to impart to 3,584,968 6/1971 Keith 415/215the flow an axial direction FOREIGN PATENTS OR APPLICAT1ONS 813,3372/1937 France 415/120 16 Claims, 10 Drawing Fi res US. atsnt Dec. 9,1975 Sheet 1 of6 3,924,963

US. atent Dec. 9, 1975 Sheet 2 of6 3,924,963

atsnt Dec. 9, 1975 Sheet 4 of 6 3,924,963

US. Patent Dec. 9, 1975 shw 6 of6 3,924,963

TURBOMACHINE The invention relates to turbomachines having improvedstructural and operational characteristics. The turbomachine is of thetype having at least a single stage radial flow runner comprising amultiplicity of vanes or fluid reaction surfaces in an axial flowhousing. Particularly, the runner of at least one stage is arranged toprovide a centripetal inducer portion integrally combined with acentrifugal impeller portion to form a single radial inward-outward flowrunner (hereinafter integral runner). The turbomachine of the presentinvention achieves a novel flow pattern in the machine through thecombination with the integral runner of a stationary annular diffusorcascade arranged downstream of the integral runner. As an incident tothe novel flow pattern, the turbomachine provides that the fluid, eithera liquid or gas, undergoes an increase in total pressure through eachstage of the turbomachine. This pressure increase is substantiallygreater than that obtained by solely an outward flow impeller runner ofthe prior art having equal diameter and flow rate and moving at an equalrotational speed.

Without any limiting intent, the turbomachine of the present inventionmay have application as a fan, a blower, or a turbine pump having nomore than approximately medium head per stage.

The prior art includes turbomachines including runners providing incombination a centripetal impeller and a centrifugal impeller. While theprior art devices of this type superficially resemble the integralrunner of the present invention, the intended function and the actualeffects of the integral runner are quite distinct from and not satisfiedby the prior art devices.

The prior art devices of the above type are easily contrasted with theintegral runner of the present invention. The prior art devices sufferfrom certain disadvantages and generally are considered unsuitable foruse in turbomachines intended for the purpose of increasing the pressurein a fluid. More particularly, in centripetal type impellers there is atendency that the centrifugal forces counteract the pressure generatingcapability of the curved vanes. At flow volumes less than the designflow, the pressure decreasing effect of the centrifugal forces acting onan inward flowing fluid is particularly pronounced. The pressure gain bythe vane action may be overcome, resulting in a net pressure loss. Thus,the purpose of the turbomachine is obviated.

It is generally recognized that, in pressure increasing turbomachines,it is advantageous to have an outward flow. In addition to the staticpressure rise caused by the flow deflecting action of the vanes, thecentrifugal forces acting on the outward flowing particles contribute tothe increase in static pressure. The centripetal inducer of the presentinvention serves to improve the pressure producing capabilities of theassociated centrifugal impeller rather than to produce substantialpressure increase in the flow passing through it. ln contrast, thecentripetal impeller of the prior art is intended to cause a substantialpressure increase in the flow passing through it. In the prior artdevices, the centripetal impeller and the centrifugal impeller aretreated as independent pressure producing components, combined in anadditive manner. Each could operate independently.

such that, over a considerable part of the turbomachines operatingrange, and particularly at flows below design capacity, the centripetalinducer discharges the flow into the inlet of the centrifugal portion atan unchanged or somewhat reduced pressure. Nevertheless, there iscapability of generation of static pressure far in excess of thatobtainable with a single centrifugal rotor of equal diameter and flowrate and rotating at the same speed.

The centripetal inducer accomplishes these purposes by minimizing themismatch between flow direction and the impeller vane direction at theimpeller inlet. The centripetal inducer enables the centrifugal impellerto operate with minimum shock loss over substantially all of theturbomachines capacity range.

There is no recognition in the prior art of the hydrodynamic oneness ofthe integral runner of the present invention. Whereas in many knownprior art devices, the discharge of fluid from the centripetal impellerin meridional projection follows generally a U-shaped path from thetrailing edge for entry at the leading edge of the centrifugal impellerwith the flow direction being purely axial in the impeller eye, themeridional flow direction in the present turbomachine is alongapproximately a diametric course from the trailing edge of thecentripetal inducer vanes to the leading edge of the centrifugalimpeller vanes. Thus, the centripetal inducer and centrifugal impellerare designed in a manner such that the flow in meridional projectiondoes not follow a U-shaped path in moving from the centripetal inducerto the centrifugal impeller. The integral runner is designed in a mannerto preclude satisfactory independent operation of either component.

A further shortcoming of the prior art is in the use of volute or scrolltype casing elements through which the flow approaches the centripetalrunner with an inward spiral motion having pronounced tangentialvelocity components. In some prior art proposals, the direction of thetangential fluid admission is opposite to the runner peripheralvelocity, while in others it agrees with the runner rotation. Eitherapproach is impractical. In the first case, the counte r-rotation of therunner against the tangentially entering fluid prevents the fluid fromdistributing itself uniformly around the runner periphery. In thesecond, although the co-rotation assists in drawing the fluid into thescroll type inlet casing, the fluid would have to reverse its directionat the vane tips by nearly in order to enter the vane channels since thecentripetal runner must have forwardly curved vanes. Apart from theimpossiblity of this abrupt reversal, it is generally recognized amongthose skilled in the art that fluid co-rotation in the runner approachdiminishes the pressure generating capacity of any type of turbomachinerunner. However. in multistage compressors and high head per stage pumpsthe use of tangential admission is unavoidable since in such machinesthe high-velocity discharge whirl of the fluid coming from the precedingcentrifugal impeller cannot be removed by statinary straightener vaneswithout causing the flow to choke in the straightener channels.

The turbomachine of the present invention successfully overcomes theobjections, difficulties, and disadvantages inherent in volute typecasings by providing an annular inlet passage upstream of and co-axialwith the centripetal inducer. It is through this passage that the fluidapproaches the periphery of the centripetal inducer in uniformdistribution and in a purely axial di rection, i.e., without tangentialvelocity components. An annular guide baffle radially adjacent theintermediate shroud member deflects the flow inwardly into thecentripetal inducer. The guide baffle also serves as a wall separatingthe low pressure inlet region and the high pressure discharge region.The guide baffle may be attached to the tubular outer casing and thusstationary or it can take the form of a radial extension of theintermediate shroud member between the centripetal inducer andcentrifugal impeller portions to rotate with the integral runner andform a running clearance with the outer casing. This will be discussedbelow. The prior art also includes axial flow inducers to improve theoperating characteristics of the centrifugal impeller. These inducershave the general appearance of a propeller or screw-type auger. Theprior art axial inducer has application primarily in pumps for thepurpose of suppressing cavitation rather than to generate a higheroverall static pressure by the runner.

It is known by those skilled in the art that the pressure generated byan outward flow runner of given design is determined by the runnerdiameter and by the speed at which the runner is rotating. In apractical situation the magnitudes of these two parameters have definitelimits dictated by considerations of structural strength, permissibleweight and size, available prime mover speeds, and other factors. Thus,the pressures obtainable from a single outward flow runner of givendesign are clearly circumscribed. In those applications which requirepressures higher than can be produced by a single outward flow runnerunder a given set of parameters, it is necessary to utilize a multistagemachine having two or more outward flow runners arranged in series onthe same drive shaft. In a multistage turbomachine each outward flowrunner after the first one receives its inlet flow from the discharge ofthe preceeding outward flow runner. However, this transfer of fluid fromone outward flow runner to a following runner on the same axis cannot beeffected in a direct manner. In this connection, the fluid which leavesthe first runner at its outer periphery with a high velocity havingradial and circumferential components must enter the following runnereye at a much lower velocity and have essentially axially components ofdirection. Stationary flow guiding apparatus, known as interstagediffusers and return channels, has to be interposed between successiverunners of a multistage turbomachine in order to bring about the changesin flow velocity and flow direction necessary for the transfer of fluidfrom one runner to the next. The use of these interstage flow guidingdevices entails considerable complexity of design and results insubstantial increase in space requirements and weight. It alsocontributes to the hydraulic losses in the turbomachine in the form offriction, turbulence, and clearance leakage losses. The incorporation ofthis structure into the design increases both the cost of constructionand the cost of operation of the machine.

The turbomachine of the present invention having two vane carryingrunners which are structurally combined into a single inward-outwardflow runner, as described more particularly hereinafter, is capable ofproducing two-stage action in a single stage. Therefore, the stationaryinterstage flow guiding apparatus in the prior art two-stage devices isobviated.

However, it is to be noted that the inward-outward flow runners of theturbomachine of the present invention may be staged, as required. Suchmultistaging ac tually is facilitated by the fact that the need forreturning the discharge flow of the centrifugal impeller to the inleteye of small diameter and axial access direction of prior art devices isobviated. The present invention requires only a radial inward flow atthe inlet of the following runner.

The two-stage machine employing two radial inwardoutward flow runnersaccording to the present invention will generate pressures comparable tothose achieved by a four-stage machine of prior art design having fouroutward flow runners of equal diameter and operating at the samerotational speed and flow rate. However, instead of the three requiredinterstage diffuser and return channel arrangements, the twostageturbomachine of the present invention requires only a single diffuser.

By the present invention there is provided a turbomachine havingimproved features of design and construction which is capable ofproducing static pressure substantially increased over that pressureobtained from a conventional turbomachine stage of the same diameter andoperating at the same speed and flow rate.

In a slightly different light, as should be apparent, the device of thepresent invention is capable of achieving required pressure increasewith a substantially smaller diameter runner which shall operate at thesame speed and handle the same flow of fluid as the conventionalturbomachine stage. As an incident to the smaller runner diameter andlower tip speed the noise level generated by the runner is reduced as isthe machine diameter. Further, the runner will have a smaller moment ofinertia requiring a lower motor starting torque.

In accordance with this aspect of the present invention, there isprovided a novel integral runner having a centripetal inducer and animpeller section directly cooperable to achieve a flow pattern whichassists in the result of an increase in fluid pressure through themachine. The integral runner is disposed in an axial housing. Thehousing includes guide baffle structure radially adjacent theintermediate shroud member to divert the fluid flow from a predominantlyaxial direction to a predominantly radial direction for entry to thecentrip etal inducer portion.

As a further aspect, the present invention contemplates one or moreintegral runners to be staged in an axial housing to achieve pressureincrease. In this form of the present invention which is actuallyfacilitated by the flow pattern through the machine the integral runnersare spaced apart and an interstage diffusor is disposed therebetween.The diffusor including a plurality of vanes serve to reduce the absolutevelocity of the fluid flow and increase static pressure as well as toact upon the fluid to remove all tangential velocity components so thatthe fluid leaves the diffusor vanes in purely an axial direction.

While the turbomachine of the present invention is capable of achievingrequired pressure increase, as stated, by a smaller diameter runner theturbomachine also is capable of achieving the pressure increase throughthe use of approximately one-half the number of stages (runners) ofconventional turbomachines of equal runner diameter and speed. Theoperational result achieved by the present turbomachine is most evidentfrom the plot of the same and the comparison with the plots of two priorart turbomachines, i.e., plot representations II and III (see FIG. 8).As may be appreciated, the design point pressure of the presentturbomachine is over twice that of the design point pressure ofturbomachine II and slightly less than twice that of the design pointpressure of turbomachine III. All three single stage turbomachine havethe same runner diameter and rotational speed.

Since the integral runner of the present invention is capable of meetingpressure requirements utilizing substantially one-half of the stagesrequired by the prior art, the present invention obviates the need foradded interstage diffusors and, accordingly, not only reduces cost,space, and weight requirements but also reduces the extent of hydrauliclosses in the turbomachine in the form of friction, turbulence, andclearance leakage losses introduced by the staging apparatus.

As a further aspect of the present invention, the integral runnerprovides a novel fluid flow pattern through the turbomachine. Moreparticularly, the flow pattern follows generally a diametric courseacross the center line of the turbomachine from the trailing edge of acentripetal inducer vane to the leading edge of a centrifugal impellervane.

A further aspect of the present invention contemplates an integralrunner which has particular application in small turbomachine. In thisconnection, the shaft carrying the integral runner does not extendthrough the flow carrying center portion. In this connection, the shaftdoes not take up too much of the space available for the flow.

An additional aspect of the present invention resides in the dispositionof the inlet opening to the first stage integral runner. To this end,the inlet opening is radially inward from all directions. This form ofinlet also provides that the fluid flow approaching the periphery of thecentripetal inducer is substantially free from tangential velocitycomponents. Particular application may be in the yield of submersiblepumps.

In yet a further aspect of the present invention, there is provisionthat all rotating stages of the turbomachine are axially inserted intoand removed from the stationary housing. To this end, the rotatingstages are joined in order to obviate the use of stationary casingcomponents for spacing. The rotating stages provide running clearancewith guide baffle and diffusor vanes and a demarcation between areas ofdiffering pressure is maintained. A front and rear casing member providesupport for required bearing members.

The efficiency of the single-stage blower of the present invention isequivalent to that of comparable conventional single-stage blowers.Since in multi-stage machines the overall efficiency is the product ofthe stage efficiencies, and since the turbomachine of the presentinvention will produce a given pressure with one-half the number ofstages, the overall efficiency of a multistage turbomachine of thepresent invention will be superior to that of a conventionalturbomachine producing the same pressure.

A further aspect of the present invention resides in the fact that thehead-capacity curves generated by a turbomachine stage cannot bereproduced by any prior art type of turbomachine stage, radial or axial,conforming to the same set of design parameters such as a set includingrunner diameter, rotational speed, static pressure and outlet velocity;or a set including runner diameter, rotational speed, flow rate andoutlet velocity.- The present invention thus provides a type ofturbomachine covering a flow-pressure field in a novel and distinctmanner thereby opening the way for new applications and yieldingsolutions to application problems that heretofore could not be solvedunder a given set of parameters.

There has thus been outlined rather broadly the more important featuresof the present invention in order that the detailed description thereofthat follows may be better understood and in order that the presentcontribution to the art may be better appreciated. There are, of course,additional features of the present invention that will be describedhereinafter and which will form the subject of the claims appendedhereto. Those skilled in the art will appreciate that the conceptionupon which this disclosure is based may readily be utilized as a basisfor the designing of other structures for carrying out the severalpurposes of the invention. It is important, therefore, that the claimsbe regarded as including said equivalent construction and do not departfrom the spirit and scope of the invention.

In order that the invention be more readily understood the same will nowbe described in conjunction with the accompanying drawings, in which:

FIG. 1 is a view in elevation, partly in section, of a multistageturbomachine and the novel integral runner assembly;

FIG. 2 is a view similar to FIG. 1 yet illustrating a single stageturbomachine;

FIG. 3 is a view similar to, yet a slight variation of, the single stageturbomachine of FIG. 2;

FIG. 3A is a view in front elevation of the turbomachine of FIG. 3illustrating the inducer vanes and inner inlet casing;

FIG. 3B is a view in rear elevation of the turbomachine of FIG. 3illustrating the drive mechanism for the drive shaft and the stationaryannular diffusor cascade;

FIG. 4 is a view in section illustrating a multistage turbomachinesimilar to the turbomachine of FIG. 1;

FIG. 5 is a view in section illustrating a turbomachine having a radialinlet to the first stage integral runner;

FIG. 6 is a view in section illustrating an integral runner having anopen flow path between inducer and impeller sections;

FIG. 7 is a perspective view of the integral runner; and

FIG. 8 is a plot of operation of the turbomachine of the presentinvention andcertain prior art turbomachines, the plots locating thedesign point of the several turbomachines.

The turbomachine illustrated in FIG. 1 is of multistage construction,i.e., the apparatus includes at least a pair of integral runners of thepresent invention. The integral runners are disposed between an inletduct 12 and an outlet duct 14. The fluid entering at the inlet issubjected to the operating conditions of the integral runners andassociated structure and undergoes an increase in static pressure duringflow through a housing from the left to right in FIG. 1.

The housing is generally indicated by the numeral 16 and includes aplurality of tubular duct sections 18, 20 and 22 comprising an inletouter casing, an interstage outer casing and a discharge outer casing,respectively. These casing members, and there may be a plurality ofinterstage components, as required, are axially arranged one to theother.

Each interstage outer casing carries an annular flange at opposed ends.The flange facilitates mounting the duct sections to one another and tothe inlet and outlet ducts which carry a flange construction on one endonly. Any particular mechanical mounting structure may be employed forthis purpose.

An inlet inner casing 24 is disposed within and in coaxial relation tothe inlet outer casing. The inlet inner casing includes an inwardlyflared downstream end 25. A plurality of members 26 are carried by theinlet outer casing and extend inwardly of the casing at spacedcircumferential positions. Preferably, two or more members 26 areprovided to support the inlet inner casing. As best seen in FIG. 3A,four members are provided for this purpose. Each member is formed by asubstantially flat plate. The inner edge of each plate may be formed tocomplement the contour of the inlet inner casing. Each member may bewelded or by any other convenient means mechanically joined to the inletinner casing at the junction.

The members, in addition to providing support for the inlet innercasing, also assist in eliminating undesirable tangential velocitycomponents in the flow of entering fluid and guide the fluid in a purelyaxial direction toward the first of the integral runner assemblies.

FIG. 1 illustrates a pair of integral runners denoted generally by thenumerals 28,30. The integral runners are supported for rotation aboutthe axis of the duct members. To this end, the integral runner 30 issupported by a shaft 32. The integral runner 28 is supported by anoverhung section 34 of the shaft.

A pair of elements support the shaft components within the ductsections. In this connection, an inner casing 36 supports the forwardend and an inner casing 38 supports the rearward end of shaft 32. Theinner casing 36 may be referred to as an interstage inner casing becauseof the disposition between the integral runners 28 and 30. A pluralityof diffusor vanes 40 positioned circumferentially support the interstageinner casing in coaxial relation to the housing. One circumferentialgroup of diffusor vanes supports an individual inner casing. Thediffusor vanes are carried by a duct section 20, 22 to project towardthe axis thereof for connection with the inner casings 36, 38.

The faces of the diffusor vanes are somewhat curved. The vane outlineand spacing may be seen more clearly in FIG. 3B. The diffusor vanes, inaddition to the support function, provide operational functions in theircascade relation as will be discussed.

The interstage inner casing 36 includes a cylindrical body 42. The bodyterminates in an inwardly flared downstream end 44. A disc shaped wall46 having a central aperture 48 is disposed within and perpendicular tothe walls of the body 42.

The inner casing 38 which may be referred to as a discharge inner casingis formed generally similar to the interstage inner casing. Thus, thedischarge inner casing 38 includes a cylindrical body 50 having adownstream truncated wall portion 52. A disc shaped wall 54 having acentral aperture 56 is disposed within and perpendicular to the walls ofthe body 50.

Shaft 32 is received through the central wall apertures and supported bybearing elements 58, 60. The bearing elements are mounted by the walls46, 54. Shaft section 34 is carried by the bearing 58. The shaftprojects forwardly of the duct sections toward the inlet 12.

A hub 62 mounts the intergal runner 28. A hub 64 mounts the intergalrunner 30. Each integral runner is positioned relative to other intergalrunners within the turbomachine for rotation. To this end, intergalrunner 28 is positioned by the bearing 58 at one end and a nut andwasher assembly 66 at the other end. The intergal runner 30 ispositioned on the shaft 32 by means of a pair of collars 68 secured tothe shaft.

Each intergal runner includes a centripetal inducer portion 70 and acentrifugal impeller portion 72. The first stage centripetal inducer 70,i.e., the inducer of integral runner 28, centripetal includes at theinlet a plurality of blades or vanes 74. Preferably, the vanes arecurved. Centripetal inducer sections of subsequent integral runnerslikewise include at the inlet a plurality of vanes 76. As with vanes 74,the vanes 76 also are preferably curved. A plurality of contoured vanes78 are disposed at the outlet of the centrifugal impeller portrons.

The outer ends of vanes 74(or 76), and 78 are attached to a front shroud80 and a back shroud 82, respectively. The inner ends of the vanes areattached to an intermediate shroud 84. Both the front and back shroudmembers are attached to the respective hubs, as illustrated in FIG. 1.

A guide baffle 104 is positioned axially within the fluid flow path. Thebaffle may be supported between the flanges of the inlet and interstageouter casings. The baffle includes a central cylindrical opening andprovides a face that may be normal to the flow but preferably the faceis inclined to the flow as illustrated in FIG. 1. The central openingpermits a running clearance with the intermediate shroud member 84. Asecond guide baffle 108 similarly formed is disposed between the flangesof the interstage and discharge outer casings. The guide bafflestogether with the flared surfaces 25 and 44 define an inlet opening tothe several integral runners and also serve the important function ofdeflecting the axial fluid flow to one of predominantly radial path.

A motor -serves as a prime mover for rotating the shaft 32 and theoverhung section 34 as well as the integral runners. To this end, themotor includes power shaft 92. A pulley wheel 94 is carried by the shaftwhile a second pulley wheel 96 is carried by shaft 32. A belt 98including a plurality of individual belt elements drivingly connects themotor shaft 92 and runner shaft 32.

The motor is mounted by the discharge outer casing 22 at or near theoutlet duct 14. A duct 100 encloses the belt. The duct is supported bythe truncated wall portion of the discharge inner casing and by thedischarge outer casing 22. The turbomachine is supported by base members102.

In operation, fluid is drawn into the turbomachine and flows past thesupport members into the annular region 110. The flow, because of thesupport members 26, is in an axial direction and contains no tangentialvelocity components. The flow is diverted from a purely axial directionby means of the guide baffle 104 (and 108 with regard to the secondintegral runner assembly) to predominantly a radial direction for entryinto the centripetal inducer 70. Flow of fluid passes the guide baffleand flared end 25. The guide baffle 104 (and 108), as may be apparent,also serves to separate a low pressure inlet flow to the integral runnerassembly from high pressure outlet flow exiting the centrifugal impeller72 of the integral runner.

The flow passing the circumferentially spaced vanes 74 traverses thecentripetal inducer portion by following generally a diametric coursethrough the flow area from the trailing edge of a centripetal inducervane to the leading edge of a centrifugal impeller vane. Theintermediate shroud member separates the centripetal fluid flow passingbetween the vanes 74 from the centrifugal fluid flow passing from theintegral runner through the vanes 78.

Flow of fluid into and through the turbomachine is represented by theseveral directional arrows in the figure.

Flow of fluid continues toward the second integral runner. The flowfollows a course past the cascade diffusor vanes 40. As will be broughtout, the diffusor vanes have a dual effect on the flowing fluid. On theone hand, the vanes serve to increase static pressure of the fluid byreducing the absolute velocity of the fluid. On the other hand, and asan inherent consequence thereof, the diffusor vanes serve to remove alltangential velocity components from the flow. In this connection, thefluid leaves the area of the cascade diffusor vanes in a purely axialdirection. The fluid is now in a suitable condition for entry into thesecond stage centripetal inducer. In a manner similar to baffle guide104, the baffle guide 108 acts upon the flow of fluid to cause analteration to a predominantly radial direction. The flow of fluid entersthe second stage centripetal inducer through the opening defined by thebaffle 108 and the flared end 44 of the interstage inner casing.

The fluid in the second stage is acted upon in a manner similar to theaction of the first stage. Upon exiting the second stage, the fluid flowis acted upon by a further cascade of diffusor vanes 40. The truncatedwall of the discharge inner casing 52 in cooperation with the wall ofthe discharge outer casing acts as an annular diffusor to impart to thefluid a further gain in static pressure prior to exiting theturbomachine by the outlet duct 14.

The embodiment of FIG. 2 generally resembles the embodiment of FIG. 1.The FIG. 2 embodiment, however, represents a single stage unit. In thisfigure, components, which duplicate those components of FIG. 1 areidentified by like references.

In FIG. 2 the outer casing is formed of a single cylindrical member 150.A pair of flanged rings 152, 154 are slideably received at opposite endsof the outer casing. Preferably, the flanged ring 152 is removablyfastened to the outer casing. The flanged ring 154 may be permanentlyattached to the outer casing. An inlet and outlet duct (not shown) maybe attached to the outer casing by mounting the same to the flangedrings in any convenient manner.

A plurality of support members 26 are carried by the flange ring 152.The members are of flat plate construction yet differ slightly from theplates 26 in overall shape. In this connection, the plates generally aretriangular. They are carried by the flanged ring 152 and support boththe inlet inner casing 24 and the guide baffle 104.

The integral runner 28 is similar to the runner of the FIG. 1embodiment. It distinguishes, however, in the construction of theintermediate shroud member 156 which connects the centripetal inducerand centrifugal impeller portion of the integral runner. To this end,the member 156 includes a radial extension 158. The extension terminatesadjacent the wall of the outer casing 150 and assists the guide baffle104 in partitioning the low pressure inlet region 160 and a highpressure discharge region 162.

The integral runner 28 is carried by hub 62 which, in turn, is carriedbythe extension 34 of shaft 32. Suit able mechanical fasteners 164 jointhe hub to the back shroud 82 of the runner.

The inner casing 50 is supported by cascade diffusor vanes 40. Thecasing substantially duplicates the discharge inner casing of FIG. 1. Tothis end, it comprises a forward cylindrical portion 166, an end wall168 including a central opening, and a rear truncated portion 170. Abracket 172 carried within the inner casing by 10 means not shownsupports a pair of bearings 174, 176. Shaft 32 is rotatably mounted bythe bearings.

A base element 178 supports the single stage unit.

FIG. 3 illustrates a slight variation of the turbomachine of FIG. 2. Thedifference may be appreciated from the following discussion. In the FIG.3 embodiment, the support member 26" mounts only the guide baffle 104.The inlet inner casing 200 is connected to or integral with the frontshroud 202 of runner assembly 28. The rear portion inner casing 50 iscylindrical like the forward portion 166.

FIG. 4 is illustrative of a typical crosssection of a multistageturbomachine in an axial flow casing 250. In the embodiment, a shaft 32is illustrated as supporting a plurality of three integral runners 252,254, and 256. The shaft is supported by a pair of bearings, the rearbearing being shown at 258. It has been found that two bearings aresufficient to support the runner shaft and consequently, since thisstructure is all that need be connected to the outer casing, it ispossible in a multistage machine, such as FIG. 4, to form all innercasings excepting the first and last as cylindrical spacing bodies ofimpeller diameter. As illustrated, the back shroud 260 of each integralrunner is connected to an axial extension 262 of the front shroud 264 ofa following centripetal inducer portion of an integral runner. Theseinner casings provide a running clearance with the vanes 266 of thecascade diffusors. The diffusors are attached to the outer casing only.

The guide baffle 268 and intermediate shroud member 270 likewise providea running clearance. The dimension of each essentially corresponds tothe dimensions of the cascade diffusor vane and the inner casing.

The inlet inner casing 272 is supported by the support members 26. Theinlet inner casing is substantially dish-shaped and carries a neckportion 174 which projects from the base. The neck carries the frontbearing 276.

The turbomachine of FIG. 4 represents an overall configuration in whichan integral runner comprising the rotating components of all stages maybe axially inserted into or removed from a stationary casing. As-

. sembly and disassembly can be accomplished after one of the twobearing-carrying inner casings at either end of the turbomachine hasbeen removed. In this manner, the complicated procedure of stackingintegral runners and stationary inner components alternately along theshaft is obviated. Manufacturing and maintenance is facilitated by thisconstruction.

A variation of the construction of, for example, FIG. 1, is illustratedin FIG. 5. The turbomachine of FIG. 5 provides a radial flow inlet 300to a centripetal inducer 302 of integral runner 304. This structure hasmany applications such as in a class of submersible pumps to beinstalled vertically in a well or form of tank. The pumping of water,oil, etc., is contemplated.

The structure comprises an outer casing 310 and an inner casing 312. Theinner casing provides a wall 314 having a central open neck portion 316.A shaft 320 is supported for rotation within the neck by a bearing 322and extends forwardly to mount the integral runner 304. An inlet casing324 comprises a guide baffle 326 and circumferentially spacedprojections 300 jutting out therefrom in a substantially axialdirection. The projections are preferably in the form of flow guidevanes. The spaces between the projections are openings for the admissionof fluid. An intermediate shroud member 328 separates the centripetalinducer and cen- 1 1 trifugal impeller portion of the integral runnerfor the reason as previously discussed.

The inlet flow of fluid to the centripetal inducer is from alldirections and radially inward toward the flow carrying center portion.Thus, the inlet flow is free of tangential velocity components.

FIG. 6 illustrates a variation of the structure of FIG. 4. Theparticular distinction is in the construction of integral runners 350and the manner of support by a split shaft 352. Thus, the flow carryingportion, like the integral runner structure of FIG. is open. A design ofthis type is particularly adapted for use in small machines in which theshaft would take up too much of the available flow space. A furtherdistinction is in the form of centripetal inducer 354 and centrifugalimpeller vane 356 including inner and outer vane edges which are notparallel to the axis of the drive shaft 352.

From the foregoing, it will be seen that, in accordance with the presentinvention, there is provided a turbomachine which satisfies the objectsof the invention and provides advantages not heretofore achieved in theturbomachine art.

Having described the invention with particular reference to thepreferred forms thereof, it will be obvious to those skilled in the artto which the invention pertains after understanding the invention, thatvarious changes and modifications may be made therein without departingfrom the spirit and scope of the invention as defined in the claimsappended hereto.

Having described the invention, 1 claim:

1. A pressure increasing turbomachine comprising a stationary housinghaving an elongated generally cylindrical chamber with a fluid flowintake at one end and a fluid flow discharge at the other end, a shaft,means for mounting said shaft for rotation within and concentric to thehousing wall, said shaft adapted to be connected to a prime mover toimpart rotation to the shaft, at least one fluid-dynamically integralrunner including a centripetal inducer and a centrifugal impeller wheelportion, each portion comprising a plurality of circumferentially spacedfluid flow energy increasing vanes within the vicinity of the peripheryof said wheel portions and an intermediate shroud member separating thevanes of one portion from the other, means for mounting said runner forco-rotation on said shaft, means including stationary straighteningvanes upstream of said centripetal portion for drawing a fluid flowsubstantially without tangential velocity components radially into saidcentripetal inducer portion, and stationary means for guiding said flowfrom said centrifugal impeller portion axially through said housing,said stationary guide means including a plurality of stationary guidevanes arranged for substantially axial through-flow downstream of saidcentrifugal impeller portion.

2. The turbomachine of claim 1 including a plurality of runners mountedon said shaft for co-rotation and means separating said runners axiallyon said shaft, said separating means defining with said housing aninterstage flow channel, and said stationary guide means for impellerflow being disposed in said channel for removing tangential velocitycomponents from said flow.

3. The turbomachine of claim 2, wherein said separating means includesan inner housing member, said stationary guide means mounting said innerhousing member within said housing.

4. The turbomachine of claim 2 wherein said separating means includes anaxial extension connecting one runner to another runner.

5. The turbomachine of claim 2 wherein said stationary guide means forimpeller flow comprise a plurality of circumferentially spaced blades,said blades being mounted to said housing to project radially inwardly.

6. The turbomachine of claim 5 wherein said separating means includes aninner housing member, said stationary guide means mounting said innerhousing member within said housing.

7. The turbomachine of claim 1 wherein said means for drawing a fluidflow into said centripetal inducer portion further comprises an inletinner casing, means mounting said inlet casing in coaxial relation tosaid housing, and an annular baffle element, means mounting said elementwithin said housing to project toward said intermediate shroud member,said baffle element diverting said fluid to predominantly a radialdirection and in cooperation with said intermediate shroud memberproviding demarcation between a pressure zone at said centripetalinducer inlet and a higher pressure Zone at said centrifugal impelleroutlet.

8. The turbomachine of claim 7, said stationary straightening vanesproviding a mounting for said inlet inner casing.

9. The turbomachine of claim 7 including a forward shroud member, saidforward shroud member mounting both said inducer vanes and said inletinner casing on said shaft 10. The turbomachine of claim 1 including arearward shroud member, said rearward shroud member mounting saidimpeller vanes on said shaft.

11. The turbomachine of claim 1 including a forward and rearward shroudmember, said forward and rearward shroud members formed as disc-shapedplates mounting said centripetal inducer and centrifugal impeller vanesto said shaft and defining the extremes of a space within said runner,said intermediate shroud member cooperating therewith to provide amultiplicity of fluid paths directed substantially obliquely throughsaid space from a centripetal inducer flow deflecting vane to acentrifugal impeller flow deflecting vane.

12. The turbomachine of claim 8 wherein said stationary straighteningvanes include plate-like members arranged circumferentially about saidhousing and extending axially toward said annular baffle element.

13. The turbomachine of claim 1 wherein said means for drawing fluidflow into said centripetal inducer portion includes a guide bafflehaving a surface directed generally toward the axis of said centripetalinducer portion, circumferentially spaced projections jutting out fromsaid surface is substantially an axial direction and defining aplurality of inlet openings arranged around the periphery of saidcentripetal inducer portion for admission of fluid thereto insubstantially a radial direction.

14. The turbomachine of claim 1 comprising a runner in which theinternal space formed by said centripetal centrifugal inducer andimpeller portions is open for unobstructed crosswise fluid flow fromsaid centripetal inducer vanes to said centrifugal impeller vanes.

15. The turbomachine of claim 1 including an inner housing memberarranged in downstream position adjacent said centrifugal impellerportion, means mounting said inner housing member within said housing,said inner housing member defining with said housing an 3,924,963 13 14annular discharge flow channel, and said stationary Y of runners arearranged and Connected Senes to form a unitary runner, said unitaryrunner capable of guide means for impeller flow being disposed in saidbeing axially removed from the housing.

channel for minimizing tangential velocity components in said flow.

16. The turbomachine of claim 4 wherein said plural- UNITED STATESPATENT OFFICE EETTMCATE OF CORRECTION PATENT NO. 3, 924,963 6 DATEDDecember 9, 1975 |NVENTOR(S) Dieter G. Zerrer It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 2 line 49, change "impossiblity" to impossibility;

Q line 58, change "statinary" to --stationary.

Column 4, line 68, change "turbomachine" to -turbomachines-. 0

Column 5, line 20, change "turbomachine" to --turbomachines-;

m line 32, change "yield" to -field--.

a Column 7, lines 58, 59, 60, 61, 63 and 66, change "intergal" to-integral-;

Column 14, line 3, change "the" to -said.

' Signed and Scaled tlus eighth Day Of June 1976 aseut fittest.

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner of Parentsand Trademark:

1. A pressure increasing turbomachine comprising a stationary housinghaving an elongated generally cylindrical chamber with a fluid flowintake at one end and a fluid flow discharge at the other end, a shaft,means for mounting said shaft for rotation within and concentric to thehousing wall, said shaft adapted to be connected to a prime mover toimpart rotation to the shaft, at least one fluid-dynamically integralrunner including a centripetal inducer and a centrifugal impeller wheelportion, each portion comprising a plurality of circumferentially spacedfluid flow energy increasing vanes within the vicinity of the peripheryof said wheel portions and an intermediate shroud member separating thevanes of one portion from the other, means for mounting said runner forco-rotation on said shaft, means including stationary straighteningvanes upstream of said centripetal portion for drawing a fluid flowsubstantially without tangential velocity components radially into saidcentripetal inducer portion, and stationary means for guiding said flowfrom said ceNtrifugal impeller portion axially through said housing,said stationary guide means including a plurality of stationary guidevanes arranged for substantially axial through-flow downstream of saidcentrifugal impeller portion.
 2. The turbomachine of claim 1 including aplurality of runners mounted on said shaft for co-rotation and meansseparating said runners axially on said shaft, said separating meansdefining with said housing an interstage flow channel, and saidstationary guide means for impeller flow being disposed in said channelfor removing tangential velocity components from said flow.
 3. Theturbomachine of claim 2, wherein said separating means includes an innerhousing member, said stationary guide means mounting said inner housingmember within said housing.
 4. The turbomachine of claim 2 wherein saidseparating means includes an axial extension connecting one runner toanother runner.
 5. The turbomachine of claim 2 wherein said stationaryguide means for impeller flow comprise a plurality of circumferentiallyspaced blades, said blades being mounted to said housing to projectradially inwardly.
 6. The turbomachine of claim 5 wherein saidseparating means includes an inner housing member, said stationary guidemeans mounting said inner housing member within said housing.
 7. Theturbomachine of claim 1 wherein said means for drawing a fluid flow intosaid centripetal inducer portion further comprises an inlet innercasing, means mounting said inlet casing in coaxial relation to saidhousing, and an annular baffle element, means mounting said elementwithin said housing to project toward said intermediate shroud member,said baffle element diverting said fluid to predominantly a radialdirection and in cooperation with said intermediate shroud memberproviding demarcation between a pressure zone at said centripetalinducer inlet and a higher pressure zone at said centrifugal impelleroutlet.
 8. The turbomachine of claim 7, said stationary straighteningvanes providing a mounting for said inlet inner casing.
 9. Theturbomachine of claim 7 including a forward shroud member, said forwardshroud member mounting both said inducer vanes and said inlet innercasing on said shaft.
 10. The turbomachine of claim 1 including arearward shroud member, said rearward shroud member mounting saidimpeller vanes on said shaft.
 11. The turbomachine of claim 1 includinga forward and rearward shroud member, said forward and rearward shroudmembers formed as disc-shaped plates mounting said centripetal inducerand centrifugal impeller vanes to said shaft and defining the extremesof a space within said runner, said intermediate shroud membercooperating therewith to provide a multiplicity of fluid paths directedsubstantially obliquely through said space from a centripetal inducerflow deflecting vane to a centrifugal impeller flow deflecting vane. 12.The turbomachine of claim 8 wherein said stationary straightening vanesinclude plate-like members arranged circumferentially about said housingand extending axially toward said annular baffle element.
 13. Theturbomachine of claim 1 wherein said means for drawing fluid flow intosaid centripetal inducer portion includes a guide baffle having asurface directed generally toward the axis of said centripetal inducerportion, circumferentially spaced projections jutting out from saidsurface is substantially an axial direction and defining a plurality ofinlet openings arranged around the periphery of said centripetal inducerportion for admission of fluid thereto in substantially a radialdirection.
 14. The turbomachine of claim 1 comprising a runner in whichthe internal space formed by said centripetal centrifugal inducer andimpeller portions is open for unobstructed crosswise fluid flow fromsaid centripetal inducer vanes to said centrifugal impeller vanes. 15.The turbomachine of claim 1 including an inner housing membEr arrangedin downstream position adjacent said centrifugal impeller portion, meansmounting said inner housing member within said housing, said innerhousing member defining with said housing an annular discharge flowchannel, and said stationary guide means for impeller flow beingdisposed in said channel for minimizing tangential velocity componentsin said flow.
 16. The turbomachine of claim 4 wherein said plurality ofrunners are arranged and connected in series to form a unitary runner,said unitary runner capable of being axially removed from the housing.